Healthy Lungs vs. Smokers’ Lungs: What You Need to Know

Medically Reviewed by Dany Paul Baby, MD on April 24, 2023
3 min read

You’ve heard it a million times: Smoking is bad for you. You may not realize, though, how much tobacco changes your lungs and their ability to bring oxygen into your body. The damage becomes clear when you look at the differences between healthy lungs and those of a smoker.

Healthy lungs look and feel like sponges. They’re pink, squishy, and flexible enough to squeeze and expand with each breath. Their main job is to take oxygen out of the air you breathe and pass it into your blood.

When you inhale, air enters your body through your windpipe, or trachea, the tube that connects your mouth and nose with your lungs. The air then travels through bronchial tubes, which move air in and out of your lungs. All along your airways, mucus and hair-like structures called cilia get rid of dust and dirt that come in with the air. Air keeps moving through your airways until it reaches tiny balloon-like air sacs in your lungs, called alveoli. From there, the oxygen moves into your blood.

When you exhale, your lungs remove carbon dioxide from your blood in a process called gas exchange.

Smoking throws this entire process out of balance.

A single puff of cigarette smoke has more than 7,000 chemicals, and almost 70 of them are known to cause cancer. When you breathe it in, these toxins go deep into your lungs and inflame them. Your airways start to make too much mucus. That leads to problems like coughing, bronchitis, and pneumonia.

Toxins make the tiny airways in your lungs swell. This can make your chest feel tight and can cause wheezing and shortness of breath. If you continue smoking, the inflammation can build into scar tissue, which makes it harder to breathe. Sticky tar from tobacco builds up inside your lungs too. After years of smoking, it can give them a black color.

The nicotine in cigarette smoke temporarily paralyzes and kills cilia. That means your airways can’t filter the dust and dirt in the air you breathe. It also makes you more likely to get colds and other respiratory infections.

Smoking also damages the alveoli, the tiny air sacs that bring oxygen into your body. Once they’re destroyed, they don’t grow back. When you lose too many of them you’ll have emphysema, a lung condition that causes severe shortness of breath.

With less oxygen coming into your body, and cigarette smoke bringing more carbon monoxide in, smoking puts all your vital organs at risk.

The moment you stop smoking, your lungs begin to repair themselves. In fact, just 12 hours after you quit, the amount of carbon monoxide in your blood drops to a healthy level. More oxygen flows to your organs, and you’re able to breathe better. The cilia in your lungs become active again too. As they recover, you might cough more at first. But that’s a sign that the cilia are helping to clear extra mucus out of your lungs.

Smoking isn’t an easy habit to break, but you’ll improve the way your lungs work if you quit. Talk to your health care provider about ways you can stop smoking.